The use of implantable catheters in the art of drug delivery and blood sampling is well known, in which at least one of several known types of catheters is implanted in a patient's system. These catheters are designed to provide repeated access to the vascular system of the patient for the purpose of performing drug delivery, blood sampling, and extracorporeal treatment of blood, such as hemodialysis and apheresis. The use of these devices reduces the trauma otherwise associated with multiple punctures of the venous system using needles for the same treatment purposes.
Implantable catheters are used to facilitate extracorporeal treatment of blood, frequent blood sampling, or provide for the delivery of medications, nutrition, blood products, and imaging solutions into the blood stream. Access to the catheter is typically accomplished by means of a luer lock extension attached to the distal end of the catheter assembly.
Implantable catheters are supplied as sterile devices, provided for single patient use only, and are available in a variety of materials, including polyurethane and silicone. A polyester cuff is sometimes formed on the catheter cannula to facilitate the anchorage of the catheter to the patient's underlying fascia, for example muscle. Implantable catheters are typically available in single and dual lumen models.
A major problem with implanted catheters is accurate placement of the tip of the catheter lumen. The tip must be placed very accurately in the patient's system in order to optimize the catheter's use and survivability. This is normally done by use of fluoroscopic guidance during implant and the addition of a radiopaque tip on the tip portion of the catheter tube aids greatly in accurate placement. Though there are many methods known in the art whereby a radiopaque tip may be placed on a catheter tube for better visualization during implantation, the use of these devices is limited by the fact that the hub to tip length of the catheter tube is conventionally fixed. This forces the surgeon to either use one length catheter for every sized patient, or to trim the tip portion of the catheter tube to customize the length of the catheter tube to the particular anatomical size of the patient. The use of one standard length for every patient is unattractive due to the fact that this typically results in excessive catheter tube being exposed outside the body after implant of the catheter on smaller patients. The conventional solution of cutting the catheter to the desired length removes the radiopaque tip portion of the catheter tube, which results in a loss of implant accuracy.
Further, the conventional process of determining the proper length for the tunnel (i.e., length from outside the body to the venotomy site) and the proper length catheter for placement in the vein to ensure that the tip is at the desired location is quite crude and imprecise. Typically, a physician places the catheter on the exterior of the patient's body and estimates the location of the desired site. This crude process is used by the physician to obtain the “proper” length for the catheter. A problem with this approach, however, is that it does not always provide the physician with the exact catheter tip placement that is desired.
What is needed, therefore, is an implantable catheter with the ability to have the catheter tip of the catheter tube positioned accurately via a radiopaque portion. The implantable catheter of the present invention also allows the length of the catheter tube to be customized to a desired length and attached to a hub member of the catheter to place the catheter tube into fluid communication with desired medical devices and/or solutions.